The invention relates to an operating mechanism of a high-rating multipole electrical circuit breaker having a pair of separable contacts per pole and comprising:
a toggle device associated with a trip member and an opening spring to move the moving contact to the open position, charging of the opening spring being carried out automatically when the closing operation is performed,
a stored energy system with an elastic device comprising at least one closing spring to move the moving contact to the closed position, charging of the closing spring being performed by a recharging cam driven in rotation by means of a manual lever or a geared motor,
a closing pawl controlled by a latching bolt to lock the cam of the stored energy system in the charged position, and to unlock the cam in the discharged position allowing the closing spring to be decompressed, the cam cooperating with a kinematic transmission chain arranged between the stored energy system and the toggle device.
The operating mechanism of the kind mentioned generally permits high-speed closing of a high-current multipole circuit breaker, due to the release of the charging cam brought about by the closing pawl being unlocked. The decompression of the closing spring ensures high-speed closing, and the spring is recharged either manually by means of a charging lever or automatically by an electric motor as soon as the circuit breaker has closed in order to be ready for another operation in the event of opening on a fault. Mechanisms of this kind for high-current circuit breakers require high operating forces which are dependent upon the characteristics and performance required, notably electrodynamic withstand, making capacity, etc . . . . Several types of interchangeable mechanisms having stored energy systems with closing springs of predetermined forces are then indispensable to meet the manufacturing requirements of a range of circuit breakers comprising basic units and units with different performances. This results in an increased mechanism storage volume, and management and production cost problems.
The present invention consists in achieving a standard mechanism for the whole range having a stored energy system with adaptable springs to choose the operating force according to the type of units.